CHANGES IN THERMAL RESOURCES OF THE VEGETATION PERIOD AND PRODUCTIVITY OF SPRING WHEAT IN THE CONDITIONS OF THE MIDDLE VOLGA REGION

The article presents the results of long-term studies (1982-2018) on assessment changes in thermal resources during growing season and indication their impact yield spring wheat. work was carried out conditions northern part Middle Volga region gray forest soils. soil experimental site is medium loamy, content humus (according to Tyurin) 2.8...3.2%, mobile phosphorus potassium Kirsanov) - 105...184 79...149 mg /100 g soil, respectively, pH- 5.6...5.8. During observation period, highest temperature increase recorded July (2.4°C) May (2.2°C), lowest June (1.0°C). sum effective temperatures over 10°C increased by 500°C study period. wheat grown without fertilizers varied greatly different years, ranging from 0.99 2.97 t/ha. value this indicator observed at an average monthly air about 13 0C May, 17 June, 18 0c July, active 1800 0c. studied resources, accordance with significance wheat, can be arranged following descending order: > above 10 °C May. To describe dependence grain three cases four, a polynomial equation second degree better suited, one case, exponential equation.